<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            width: 600px;
            height: 300px;
            border: 2px solid red;
            text-align: center;
            margin: auto;
        }

        /* div h3 {
            color: red;
        } */

        div h1 {
            color: red;
        }
    </style>
</head>

<body>
    <div>
        <h3>
           提示信息
        </h3>
        <h1>
            <%= msg %>
        </h1>
    </div>
</body>

</html>